The presence and growth of micro-organisms in aqueous systems, especially in industrial water systems, is a concern. Examples of industrial water systems where micro-organisms are a concern include, but are not limited to, cooling water systems, pulping and papermaking systems, and oil and gas field water systems.
A known method of controlling microbial growth in aqueous systems is the use of biocides. While biocides are known to inhibit microbial growth, the biocidal effect is generally of limited duration. The effectiveness of known biocides may be rapidly reduced as a result of exposure to negative influences. Negative influences may include, but are not limited to, certain temperature or pH conditions or reaction with ingredients present in the system that neutralizes their biocidal effect. Therefore, the use of such biocides may involve continuous or frequent replenishment at multiple sites or zones in the system being treated. The materials costs of the biocide treatment and the labor costs associated with the application of known biocides may therefore be significant.
Known biocides can be highly toxic in the quantities known to be required for effective control of microbial populations in certain applications. As a result, the amount of biocides that may be safely discharged into the environment may be limited by environmental regulations. Therefore, the need exists for improved methods for controlling microbial growth in aqueous systems.
As noted above, known biocides have a number of limitations including the large quantities of biocides typically required to achieve the desired biocidal effect and the potential harmful effects on the environment of biocides, and therefore reducing the amount necessary for control and thus the quantity released to the environment has many benefits.
The presence of micro-organisms in industrial water systems may result in the formation of deposits on system surfaces. These deposits or slimes may give rise to various problems. In cooling water systems, slime may restrict water flow, reduce heat transfer efficiency, cause corrosion, and be aesthetically unappealing, especially if algae are present, due to their visible green pigmentation. Corrosion may also occur in industrial water systems, even in the absence of visible slime, through the action of micro-organisms.
Pseudomonas aeruginosa are bacteria commonly present in air, water, and soil. These bacteria continually contaminate open cooling water systems, pulping and papermaking systems, and oil and gas field water systems and are among the most common slime formers. Slime may be viewed as a mass of cells stuck together by the cementing action of the gelatinous secretions around each cell. The slime entraps other debris, restricts water flow and heat transfer, and may serve as a site for corrosion.
Chlorella vulgaris are algae commonly present in air, water, and soil. These algae continually contaminate open cooling water systems and their growth turns the water and surfaces in these systems green. These algae also provide a food source for bacteria, which may stimulate slime formation and growth of protozoa, which may harbor the pathogenic bacterium Legionella pneumophila. 
In pulp and paper mill systems, slime formed by micro-organisms may cause fouling, plugging, or corrosion of the system. The slime may also break loose and become entrained in the produced paper, causing blemishes, holes, tears, and odor in the finished product. The end result may therefore be unusable product and wasted output.
Slime may also be a problem in oil and gas field water systems and may cause energy losses due to increased fluid frictional resistance, formation plugging, and corrosion. The slime may harbor a mixture of aerobic and anaerobic bacteria that are responsible for the production of hydrogen sulfide gas. The hydrogen sulfide may cause souring of oil and gas, which may reduce the quality of these products and increase treatment costs.
In order to extract oil and gas from geological formations, well treatment fluids are pumped into wells. One known process of extraction is hydraulic fracturing, also known as fracking or hydrofracking. In the fracking process, a well treatment fluid is pumped through a well bore hole into a geological formation at a high pressure to cause the creation and opening up of fractures in the geological formation.
Known additives for well treatment fluids include a blend of glutaraldehyde and a quaternary ammonium compound. Such blends are often insufficient in that the quaternary ammonium compound may not provide sufficient preservative activity. Further additives may include an oxidizing biocide and a non-oxidizing biocide separately, and a fast-acting non-oxidizing biocide and a preservative biocide may be applied to the well treatment fluid. Known oxidizing biocides include, but are not limited to, bleach, chlorine dioxide (ClO2), and stabilized chlorine. The application of separate biocide additive compositions may be cumbersome and expensive.
Accordingly, the present disclosure aims to address at least one disadvantage associated with the prior art, whether discussed herein or otherwise.